Liquid crystal display device

ABSTRACT

Disclosed are a liquid crystal display (LCD) device and a method for assembling the LCD device. The LCD device has a display section for displaying images, a receiving container for receiving the display section, a power supplying section for supplying a power source to the display section, a signal converting section for converting signals from the display section and a securing section for securing the power supplying section and the signal converting section to the receiving container. The power supplying section and the signal converting section are disposed between the display section and the securing section that is directly facing to a rear surface of the receiving container. Accordingly, a total thickness and weight of the LCD device can be minimized and an assembly facility of the LCD device can be improved

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a liquid crystal display device (LCD),and more particularly, to a LCD device of which a size and a weight arereduced.

2. Description of the Related Art

In recent times, information processing devices continue to rapidlydevelop with various architectures, functions and faster informationprocessing speed. Information processed in these information processingdevices has an electrical signal format. In order to visually confirminformation processed in the information processing device, a display asan interface should be provided.

Recently, a LCD device that is lighter, and smaller than a CRT typedisplay device has been developed. The LCD device has a full colordisplaying function and a high resolution. As a result, the LCD deviceis widely used as a monitor of a computer, a television, and anotherdisplay device.

The LCD device applies a voltage to a predetermined moleculararrangement of a liquid crystal to convert the molecular arrangement toanother molecular arrangement. The LCD device converts the changes ofoptical properties to visional changes and uses the modulation of alight by using a liquid crystal cell.

LCD devices are divided into to a TN (Twisted Nematic) type and a STN(Super-Twisted Nematic) type, and are also divided into an active matrixdisplay type that uses a switching device and a TN liquid crystal and apassive matrix display type that uses a STN liquid crystal according tothe driving type.

The active matrix display type is used in a TFT-LCD and drives an LCD byusing a thin film transistor (TFT) as a switch. The passive matrixdisplay type does not use any transistor and does not need a complexcircuit.

Further, LCD devices are divided into a transparent LCD device that usesa backlight and a reflective LCD device that uses an exterior lightsource according to a method for using a light source.

The transparent LCD device that uses the back light as a light sourcehas a heavy weight and a large volume due to the existence of the backlight, but is widely used since it independently displays an imagewithout using an exterior light source.

FIG. 1 is an exploded perspective view schematically showing aconventional LCD device 100. FIG. 2 is a sectional view showing acombination construction of the LCD device 100 shown in FIG. 1.

Referring to FIG. 1, the LCD device 100 has a LCD module 130 fordisplaying an image when an image signal is applied thereto and frontand rear cases 110 and 120 for receiving the LCD module 130. The LCDmodule 130 includes a display unit 170 having a LCD panel for displayingthe image and a backlight assembly 150 for supplying light to thedisplay unit 170.

The display unit 170 includes a LCD panel 171, a data side printedcircuit board 176, a gate side printed circuit board 175, a data sidetape carrier package 178 and a gate side tape carrier package 174.

The LCD panel 171 has a TFT substrate 172, a color filter substrate 173and liquid crystal (not shown).

The TFT substrate 172 is a transparent glass board on which the TFTs areformed in a matrix type. Data lines are respectively connected to Sourceterminals of the TFTs and gate lines connected with gate terminals ofthe TFTs. Furthermore, pixel electrodes are respectively formed at drainterminals of the TFTs, which are comprised of a transparent conductivematerial such as Indium Tin Oxide (ITO).

The color filter substrate 173 faces to the TFT substrate 172. RGBpixels are formed on the color filter substrate 173 via a thin filmprocess, which gives a predetermined color while the light passesthrough the color filter substrate 173. Common electrodes made of ITOare coated on the front surface of the color filter substrate 173.

When the TFTs of the TFT substrate 172 are turned on by applyingelectric power to the gate terminals and to the source terminals of theTFTs, an electric field is formed between the pixel electrodes of theTFT substrate 172 and the common electrodes of the color filtersubstrate 173. The electric field forces the liquid crystal, which isinjected between the TFT substrate 172 and the color filter substrate173, to change the array angle thereof resulting in that thetransmission of the light is changed. As a result, the desired pixelsare obtained.

Meanwhile, a driving signal and a timing signal are applied to the gatelines and data lines of the TFT to control the array angle of the liquidcrystal and the time of arraying the liquid crystal in the LCD panel171. As shown in FIG. 1, the data side tape carrier package 178 that iscomprised of flexible circuit boards, is attached to the source portionof the LCD panel 171 to decide a time of applying a data driving signal.On the other hand, the gate side tape carrier package 174 is attached tothe gate portion of the LCD panel 171 to decide an application time of agate driving signal.

The data side printed circuit board 176 and the gate side printedcircuit board 175, which respectively apply the driving signal to thegate line and to the data line as soon as receiving image signals inputfrom outside of the LCD panel 171, make contact with the data side tapecarrier package 178 for the data line and the gate side tape carrierpackage 174 for the gate line in the LCD panel 171, respectively. Asource portion is formed on the data side printed circuit board 176 toreceive the image signals from an information process device (not shown)such as a computer, etc. and then to provide the gate driving signal forthe gate line of the LCD panel 171 and a gate portion is formed on thegate side printed circuit board 175 to provide the gate driving signalto the gate lines of the LCD panel 171. That is, the data side printedcircuit boards 176 and the gate side printed circuit board 175 generateand apply the gate driving signal and the data signal for driving theLCD device and a plurality of timing signals for applying the gatedriving signal and the data signal to the gate lines and the data linesof the LCD panel 171, so as to provide the gate driving signal throughthe gate side tape carrier package 174 to the gate lines of the LCDpanel 171 and to supply the data signal through the data side tapecarrier package 178 to the data lines of the LCD panel 171.

The backlight assembly 150 is provided under the display unit 170 touniformly supply the light to the display unit 170. The backlightassembly 150 includes lamp units 161 and 162, which are disposed at bothends of a LCD module 130, for generating the light, a light guide plate152 for guiding the light emitted by the lamp units 161 and 162 towardthe display unit 170 by changing a pathway of the light, a plurality ofoptical sheets 153 for uniformly making a brightness of the light whichis transmitted from the light guide plate 152 and a light reflectingplate 154, which is provided under the light guide plate 152, forreflecting a leaked light to the light guide plate 152 so as to improvethe efficiency of the light

The display unit 171 and the backlight assembly 150 are successivelyreceived in a mold frame 132 used as a receiving container. The moldframe 132 is provided with a top chassis 140, which faces and iscombined with the mold frame 132, for preventing the display unit 171from departing from the mold frame 132.

Meanwhile, the LCD device further includes a power supply printedcircuit board 135, which has an inverter circuit for supplying the powersource to the lamps of the lamp units 161 and 162 and a signalconversion printed circuit board 134 for converting and providing outerdata signals to the data side printed circuit board 176.

The power supply printed circuit board 135 and the signal conversionprinted circuit board 134 are fixed to a rear surface of the bottomchassis 131 by means of a bracket 133, as shown in FIGS. 1 and 2.Particularly, when the top chassis 140 is assembled with the mold frame132 to form the LCD module 130, the LCD module 130 is received in thefront case 110. The power supply printed circuit board 135 and thesignal conversion printed circuit board 134 are combined to the rearsurface of the bracket 133 by means of the screws 134 c, 134 d and 135 bso that supports 134 a, 134 b and 135 a are disposed between the rearsurface of the bracket 133 and the power supply printed circuit boards135 and the signal conversion printed circuit board 134. The bracket 133is combined with the front case 110 by means of screws 133 a and 133 b.

Then, a shield case 136 is disposed at the rear surface of the bracket133 to enclose the power supply printed circuit board 135 and the signalconversion printed circuit board 134. The shield case 136 insulates anelectromagnetic wave generated form the LCD module 130 including thepower supply printed circuit board 135 and the signal conversion printedcircuit board 134.

As described above, when the bracket 133 and the shield case 136 arecombined to the rear surface of the LCD module 130, the rear case 120 iscoupled to the front case 110 and supported by the support 180 tocomplete the LCD monitor device (see FIG. 3).

As shown in FIG. 2, the power supply printed circuit board 135 and thesignal conversion printed circuit board 134 are mounted on the rearsurface of the LCD module 130 by the combination with the bracket 133having a predetermined height. Further, the shield case 136 is coupledto the rear surface of the bracket 133 by means of the screws 136 a and136 b.

In the conventional LCD device, there are many problems as follows.

Firstly, with reference to FIG. 2, the thickness t1 of the LCD deviceincreases to the extent of the heights of the bracket 133 and the shieldcase 136 and the heights of the supports 134 a, 134 b and 134 a forfixing the power supply printed circuit board 135 and the signalconversion printed circuit board 134 to the bracket 133. Particularly, athickness t2 of a rear surface of the LCD device greatly increases dueto the bracket 133 and the shield case 136 as shown in FIG. 4.

Secondly, since the power supply printed circuit board 135 and thesignal conversion printed circuit board 134 are installed to be adjacentto both ends of the bracket 133, an area of the shield case 136 isexcessively wide for covering them. Thus, the end portion of the LCDdevice is as thick as the center portion of the LCD device.

Thirdly, since the power supply printed circuit board 135 and the signalconversion printed circuit board 134 are placed at a position far awayfrom the lamp units 161 and 162 and from the data side printed circuitboard 176, as not shown in detail in drawings, there is a problem inthat a line for supplying the power and a line for transferring thesignals are longer. Furthermore, when the line for supplying the powerand the line for transferring the signals are longer, it becomesdifficult to include and to fix the lines to the LCD module 130 in astable fashion.

SUMMARY OF THE INVENTION

The present invention has been made to solve the aforementioned problem,and accordingly it is an object of the present invention to provide aLCD device in which a total size and a weight can be reduced.

It is another object of the present invention to provide a LCD device inwhich a size can be minimized by using a support for rigidly making aninstallation of the LCD device.

To achieve objects of the present invention, a LCD device according toan embodiment of the present invention includes displaying means fordisplaying image; receiving means for receiving the displaying means; aprinted circuit board mounted on a back surface of the receiving means,for controlling an operation of the displaying means; and shieldingmeans mounted on the back surface of the receiving means for shieldingelectromagnetic waves from the printed circuit board. The shieldingmeans is mounted on a center portion of the back surface of thereceiving means while enclosing the printed circuit board so that edgesof the receiving means are exposed at a predetermined width.

The receiving means includes a bottom chassis for receiving thedisplaying means and a mold frame having a bottom surface opened so thata back surface of the bottom chassis in which the printed circuit boardis mounted is exposed, for receiving the bottom chassis. The printedcircuit board may be a power supplying means mounted on the back surfaceof the receiving means, for supplying the power to the displaying means,and a signal converting means mounted on the back surface of thereceiving means, for converting signals supplied to the displayingmeans.

Furthermore, the displaying means includes an integrated and printedcircuit board electrically connected to the signal converting means anda flexible printed circuit board, for controlling the operation and anoperating time of the displaying means in response to the signals fromthe power supplying means and from the signal converting means.

The LCD device further includes a power supplying line for supplying thepower from the power supplying means to a lamp of the displaying meansand a securing member for securing the power supplying line for the lampto the back surface of the receiving means.

The securing member includes a belt type securing band, having first andsecond through-holes at each end thereof and bent so that the first andsecond through-holes are opposite to each other to receive the line forsupplying the power to the lamp and a first locking screw that extendsthrough the first and second through-holes of the securing band bent toreceive the line for supplying the power to the lamp, for securing thesecuring band to the bottom chassis.

In order to achieve another object of the present invention, a LCDdevice according to the other embodiment of the present inventionincludes a displaying device; a front case for receiving the displayingdevice in front of the displaying device; and a rear case combined withthe front case in back of the displaying device, wherein the rear casehas a region projecting at a predetermined height to receive theshielding means.

The displaying device has displaying means for displaying the image,receiving means for receiving the image displaying means, a printedcircuit board mounted on a back surface of the receiving means, forcontrolling an operation of the displaying means, and shielding meansmounted at a center portion of the back surface of the receiving means,for shielding electromagnetic waves from the printed circuit board; afront case for receiving the displaying device in front of thedisplaying device; and a rear case combined with the front case in backof the displaying device, wherein the rear case has a region projectingat a predetermined height to receive the shielding means.

The LCD device may further include an abutment combined with theprojected region in a back surface of the rear case, for supporting thedisplaying device.

In the LCD device according to the present invention, an inverter boardand an analog/digital board are combined with the bottom chassis to bein close contact to the back surface of the bottom chassis. The shieldcase for shielding the electromagnetic waves from the analog/digitalboard and from the inverter board only covers the analog/digital boardand the inverter board so that the edges of the bottom chassis and themold frame are exposed.

Accordingly, it is possible to manufacture the LCD device in which theedge except for a region, in which the analog/digital board and theinverter board are mounted, has the same thickness as the LCD module. Byminimizing a total thickness of the LCD device, the thinner and lighterLCD device can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects and advantages of the present invention willbecome more apparent by describing in detail the preferred embodimentsthereof with reference to the accompanying drawings, in which:

FIG. 1 is an exploded perspective view schematically showing aconventional LCD device;

FIG. 2 is a sectional view showing a combination construction of the LCDdevice shown in FIG. 1;

FIGS. 3 and 4 are perspective views showing an exterior of a LCD deviceshown in FIG. 1;

FIG. 5 is an exploded sectional view showing a LCD device according to apreferred embodiment of the present invention;

FIG. 6 is a sectional view showing a combination construction of the LCDdevice shown in FIG. 5;

FIG. 7 is a sectional view showing a back surface of a bottom chassisand a mold frame of the LCD device shown in FIG. 6;

FIG. 8 is a view showing a construction of an inverter board and ananalog/digital board combined with the bottom chassis shown in FIG. 7;

FIG. 9 is a view showing the LCD device, in which the integrated printedcircuit board is combined with a back surface of the LCD device shown inFIG. 8:

FIGS. 10 and 11 are views showing states in that a power supply line fora lamp shown in FIG. 8 is connected to a back surface of the LCD deviceby means of a fixing member according to an embodiment of the presentinvention;

FIGS. 12 and 13 are views showing states in that a power supply line fora lamp shown in FIG. 8 is connected to a back surface of the LCD deviceby means of a securing member according to another embodiment of thepresent invention;

FIG. 14 is a plan view showing a construction of a shield case shown inFIG. 5;

FIG. 15 is a view showing a state in that a shield case is combined withthe back surface of the LCD device shown in FIG. 9; and

FIGS. 16 and 17 are perspective views showing an exterior of the LCDdevice shown in FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, LCD devices according to the preferred embodiments of thepresent invention will be described in detail with reference to theaccompanying drawings.

FIG. 5 is an exploded perspective view schematically showing a LCDdevice according to a preferred embodiment of the present invention.

Referring to FIG. 5, the LCD device 200 includes a LCD module 230 fordisplaying an image when an image signal is applied thereto and a casethat has front and rear cases 210 and 220, for receiving the LCD module230.

The LCD module 230 can be generally and functionally divided into asection for displaying the image, a receiving container for receivingthe displaying section and a section for controlling an operation of thedisplaying section.

Particularly, the displaying section has a display unit 270 including aLCD panel 271 and a backlight assembly 250 for supplying a light to thedisplay unit 270. The receiving container has a bottom chassis 300 forreceiving the display unit 270 and the backlight assembly 250 and a moldframe 600 for receiving and supporting the bottom chassis 300, of whicha bottom surface is opened to expose a rear surface of the bottomchassis 300.

Furthermore, the section for controlling the operation of the displaysection has a printed circuit board 500 (hereinafter, referred to as aninverter board 500) for supplying the power to the displaying sectionand a printed circuit board 400 (hereinafter, referred to as an A/Dboard 400) for converting a signal provided to the displaying section. Ashield case 700 is disposed between the receiving container and the rearcase 220 to shield an electromagnetic wave discharged from the inverterboard 500 and the A/D board 400.

Hereinafter, a construction of the LCD device as described above will beexplained in detail.

The display unit 270 has the LCD panel 271, a panel-driving printedcircuit board 276 (hereinafter, referred to as an integrated PCB 276)for operating the LCD panel 271, a data side tape carrier package 278and a gate side tape carrier package 274.

Here, the integrated PCB 276 contains a gate line driving circuitconnected to the gate side tape carrier package 274 to drive a gate lineof the LCD panel 271 and a data line driving circuit connected to thedata side tape carrier package 278 to drive a data line of the LCD panel271.

That is, the gate side tape carrier package 274 contains a wiringpattern for providing signals driving the gate line to the LCD panel 271and a connector for electrically connecting the gate side tape carrierpackage 274 to the integrated PCB 276. The integrated PCR 276 Iscombined through the data side tape carrier package 278 with a side ofthe LCD panel 271. A detail of a pathway through which the drivingsignals for driving the gate line and the data line are transmitted willbe described below.

Meanwhile, since the integrated PCB 276 is constructed of the drivingcircuits of the gate printed circuit board and the data printed circuitboard that are respectively made are integrated in one piece,high-density packaging techniques are required for packaging theintegrated PCB 276. In the present invention, by applying a method of achip on glass, parts of the gate driving circuit and the data drivingcircuit may be installed on the board not in a package but in a chip ora part by wire bonding and bumping.

The LCD panel 271 comprises a TFT substrate 272, a color filtersubstrate 273 and a liquid crystal (not shown).

The TFT substrate 272 is a transparent glass substrate on which TFTs ina matrix type are formed. A data line is connected with source terminalsof the TFTs and a gate line is connected with gate terminals of theTFTs. Furthermore, pixel electrodes made of ITO, which is a transparentand conductive material, are formed at drain terminals of the TFTs.

When electric signals are applied to the data line and to the gate line,the electric signals are input into the source terminals and the gateterminals of the respective TFT. As the electric signals are input intothe TFTs, the TFTs are respectively turned-on or turned-off, resultingin outputting the electric signals, which are required to form pixels,to the drain terminals.

The color filter substrate 273 is provided to face to the TFT substrate272. The color filter substrate 273 has RGB pixels, which are formed bya thin film process to give desired colors while the light passesthrough the color filter substrate 273. A surface of the color filtersubstrate 273 is coated with common electrodes made of ITO.

When the electric power is applied to the gate and source terminals ofthe transistors on the TFT substrate 272 to turn on the TFTs, anelectric field is formed between the pixel electrodes and commonelectrodes of the color filter substrate 273. This electric fieldchanges an array angle of the liquid crystal injected between the TFTsubstrate 272 and the color filter substrate 273, resulting in that alight transmissivity depending on the changed array angle also ischanged so as to produce the desired pixels.

A driving signal and a timing signal are applied to the gate line and tothe data line of the TFTs to control the array angle of the liquidcrystal and the time at which the liquid crystal is arranged in the LCDpanel 271.

As shown in FIG. 5, the data side tape carrier package 278, which iscomprised of flexible circuit boards, is attached to the source portionof the LCD panel 271 to decide a time at which a data driving signal isapplied to the LCD panel 271. On the other hand, the gate tape carrierpackage 274 is attached to the gate portion of the LCD panel 271 todecide a time at which a gate driving signal is applied to the LCD panel271.

The integrated PCB 276, which applies the driving signal to the gateline and to the data line as soon as receiving image signals input fromoutside of the LCD panel 271, makes contact with the data side tapecarrier package 278 for the data line in the LCD panel 271. A sourceportion and a gate portion are formed on the integrated PCB 276. Thesource portion receives the image signals from an information processingdevice (not shown) such as a computer, etc. and then provides the datadriving signal for the data line of the LCD panel 271. The gate portionprovides the gate driving signal for the gate line of the LCD panel 271.

That is, the integrated PCB 276 generates the gate driving signal andthe data signal for driving the LCD device and the plural timing signalsfor applying the gate driving signal and the data signal in anacceptable time, so as to apply the gate driving signal through the gateside tape carrier package 274 to the gate line of the LCD panel 271 andthe data signal through the data side tape carrier package 278 to thedata line of the LCD panel 271.

However, it can be noted that each of the printed circuit boards can berespectively substituted for the source portion and for the gate portionformed on the integrated PCB 276. On the other hand, it is also notedthat a printed circuit board is substituted for the gate portion of theintegrated PCB 276 so as to be connected to the gate side tape carrierpackage 274 and only the source portion can be formed in the integratedPCB 276 to be connected to the data side tape carrier package 278 asshown in FIG. 5.

A backlight assembly 250 is disposed under the display unit 270 tosupply the light to the display unit 270 uniformly. The backlightassembly 250 includes first and second lamp units 261 and 262 forgenerating the light. The first and second lamp units 261 and 262respectively have two lamps.

A light guide plate 252 has a size corresponding to that of the LCDpanel 271 of the display unit 270 and is disposed under the LCD panel271 so as to guide the light generated from the first and second lampunits 261 and 262 to the display unit 270 while changing the pathway ofthe light.

Meanwhile, a plurality of optical sheets 253 are disposed on the lightguide plate 252 to make uniform the brightness of the light from thelight guide plate 252 to the LCD panel 271. Furthermore, a reflectionplate 254 is provided under the light guide plate 252 to reflect thelight leaked from the light guide plate 252 to the light guide plate252, thereby increasing the light efficiency.

The display unit 270 and the backlight assembly 250 are received in abottom chassis 300 used as a receiving container, which is fixedlysupported by means of a mold frame 600. The mold frame 600 has anopening at a bottom surface to expose the rear surface of the bottomchassis 300. Furthermore, an area of the mold frame 600 in which theintegrated PCB 276 is mounted in a bending state partially opens so thatthe mold frame 600 can receive elements installed on the integrated PCB276.

An inverter board 500 and an AID board 400 for converting signals aremounted on the rear surface of the bottom chassis 300, which is exposedthrough the opening in the bottom surface of the mold frame 600. Theinverter board 500 transforms the electric power at a predeterminedvoltage level before providing the electric power to the first andsecond lamp units 261 and 262. The A/D board 400 is connected to theintegrated PCB 276 to convert analog data signals into digital datasignals before supplying the data signals to the LCD panel 271. The A/Dboard 400 and the inverter board 600 are fixed to the bottom chassis 300by means of a securing member, for example, brackets. The fixture of theA/D board 400 and the inverter board 500, will be described below.

Meanwhile, a top chassis 240 is disposed on the display unit 270 toprevent the display unit 270 from departing from the bottom chassis 300while it undergoes bending of the integrated PCB 276 to be outside ofthe mold frame 600.

FIG. 6 is a view of showing a combination construction of the LCDmonitor device as shown in FIG. 5.

Referring to FIG. 6, the reflection plate 254, the light guide plate252, the optical sheet 253 and the display unit 270 are sequentiallyreceived in the bottom chassis 300 that is disposed in the mold frame600. The A/D board 400 and the inverter board 500 are fixed on the backsurface of the bottom chassis 300. A shield case 700 is combined to theback surface of the mold frame 600 to shield an electromagnetic wavedischarged from the A/D board 400 and from the inverter board 500 whileenclosing the A/D board 400 and the inverter board 500.

Also, the A/D board 400 and the inverter board 600 are concentricallymounted at a center portion of the back surface of the bottom chassis300. Accordingly, the shield case 700 results in a small size andencloses the A/D board 400 and the inverter board 500.

In other words, the shield case 700 does not cover the back surfaces ofthe bottom chassis 300 and the mold frame 600 entirely, but only coversthe bent integrated PCB 276 on the back surfaces of the A/D board 400,the inverter board 500 and the mold frame 600. Accordingly, even thoughthe shield case 700 is combined to the bottom chassis 300, the edges ofthe bottom chassis 300 and the mold frame 600 are partially exposed.

Then, the front case 210 and the rear case 220 are respectively combinedwith the top chassis 240 and the shield case 700 to cover the exposededges of the bottom chassis 300 and the mold frame 600, therebycompleting the assembly of the LCD device.

As shown in FIG. 6, in the LCD device, the thickness t3 of the edgeportion on which the shield case 700 is not covered is thinner than thethickness t4 of the center portion on which the shield case 700 iscovered. The thickness of the LCD device will be described withreference to the drawings.

FIGS. 7 to 9 are views of showing the constructions of the back surfaceof the LCD device as shown in FIG. 6.

Referring to FIG. 7, the mold frame 600 has a plurality of holes 620,621, 622, 623, 624 and 625 to receive the circuit elements mounted onthe integrated PCB 276. In addition, the mold frame 600 has an openingat the center portion of the bottom surface thereof so that the backsurface of the bottom chassis 300 is exposed.

The reason for forming the opening in the bottom surface of the moldframe 600 in order to expose the back surface of the bottom chassis 300is that the A/D board 400 and the inverter board 500 are faced to anddirectly fixed to the back surface of the bottom chassis 300.

If the A/D board 400 and the inverter board 500 are fixed to the bottomchassis 300 in the state that the mold frame 600 has no the opening, theA/D board 400 and the inverter board 500 are placed at a position sothat the heights thereof increase as much as the thickness of the moldframe 600. Therefore, the thickness of the LCD device cannot be furtherreduced in order that the LCD device is made thinner and smaller.

Meanwhile, a first looking hole 313 is formed in the bottom surface ofthe bottom chassis 300, in which a securing member (not shown) iscombined so as to secure a first power supply line 261 a for supplyingthe electric power to a lamp of the first lamp unit 261 to the backsurface of the bottom chassis 300. Furthermore, a second locking hole315 is formed in the bottom surface of the bottom chassis 300, in whicha securing member (not shown) is combined so as to secure a second powersupply line 262 a for supplying the electric power to a lamp of thesecond lamp unit 262 to the back surface of the bottom chassis 300. Theconstruction in that the first and second power supply lines 261 a and262 a are secured to the back surface of the bottom chassis 300 by meansof the securing members will be explained below.

First and second projections 310 and 311 are formed on the back surfaceof the bottom chassis 300 to prevent the inverter board 500 fromseparating from the bottom chassis 300 before the inverter board 500 issecured to the bottom chassis 300 by means of the screws. Similarly,third and fourth projections 320 and 321 are formed on the back surfaceof the bottom chassis 300 to prevent the A/D board 400 from separatingfrom the bottom chassis 300 before the A/D board 400 is secured to thebottom chassis 300 by means of the screws. In addition, fifth and sixthprojections 350 and 351 are formed on the back surface of the bottomchassis 300 at a predetermined distance from the third and fourthprojections 320 and 321 to help the third and fourth projections 320 and321 to prevent the A/D board 400 from separating from the bottom chassis300.

Third and fourth looking holes 340 and 342 are formed at the backsurface of the bottom chassis 300 to combine the integrated PCB 276 withthe bottom chassis 300 by means of the screws (not shown). In addition,fifth and sixth locking hole 276 a and 276 b are formed at theintegrated PCB 276 to face to the third and fourth locking holes 340 and342. At that time, the third and fourth locking holes 340 and 342, whichare used for securing the integrated PCB 276 to the bottom chassis 300,are covered with a skin of the mold frame 600. Accordingly, the moldframe 600, in which the third and fourth locking holes 340 and 342 areformed, has first and second through-holes 670 and 672 formed atpositions thereof corresponding to the third and fourth locking holes340 and 342 to expose the third and fourth locking holes 340 and 342 tothe outside.

The first and second projections 310 and 311 are formed by partiallycutting the bottom chassis 300 to guide the inverter board 500 to acombination position. Similarly, the third to sixth projections 320,321, 350 and 351 guide the A/D board 400 to a combination position.

As shown in FIG. 8, the inverter board 500 is combined to the bottomchassis 300 as moved from the first locking hole 313 to the first andsecond projections 310 and 311. When the movement of the inverter board500 is stopped by means of the first and second projections 310 and 311for preventing the inverter board 500 from being separated from thebottom chassis 300, the inverter board 500 is kept in an initialinstallation state by means of the first and second projections 310 and311 until the shield case 700 is mounted on and secured to the backsurface of the bottom chassis 300 by means of screws (not shown).

Similarly, the A/D board 400 is combined to the bottom chassis 300 asmoved from the fourth locking hole 342 to the third and fourthprojections 320 and 321. When the movement of the A/D board 400 isstopped by means of the third and fourth projections 320 and 321, theA/D board 400 is kept in an initial installation state by means of thethird to sixth projections 320, 321, 350 and 351.

As shown in FIG. 8, the A/D board 400 and the inverter board 500 areconcentrically mounted at the center portion of the back surface of thebottom chassis 300 exposed through the opened bottom surface of the moldframe 600. In FIG. 8, the back surface of the bottom chassis 300 isconsiderably exposed out of the A/D board 400 and the inverter board500.

Referring to FIG. 9, after the A/D board 400 and the inverter board 500are mounted on the bottom chassis 300, the integrated PCB 276 is bent tothe back surface of the mold frame 600 so that a connector 277 a of theintegrated PCB 276 is connected to a first connector 410 of the A/Dboard 400. At this time, the connector 277 a of the integrated PCB 276is formed in the flexible printed circuit board 277 having a conductivepattern to transmit the signals from the A/D board to the integrated PCB276.

Next, the first and second power supply lines 261 a and 262 a are guidedto the inverter board 500 along the back surface of the bottom chassis300 so as to be connected to fourth, fifth, seventh and eighthconnectors 510 a, 510 b, 514 a and 614 b formed in the inverter board500, respectively. The A/D board 400 and the inverter board 500 areconnected to each other by means of the second and ninth connectors 412and 516.

Hereinafter, a method of securing the first and second power supplylines 261 a and 262 a to the back surface of the bottom chassis 300 willbe described with reference to FIGS. 10 to 13. Since the methods ofrespectively securing the first and second power supply lines 261 a and262 a are the same, the method of securing the second power supply line262 to the back surface of the bottom chassis 300 will be explained asan example. In the embodiment of the present invention, furthermore, thefirst and second lamp units 261 and 262 respectively have two lamps.

FIGS. 10 to 13 show the state in that the power supply line for a lampshown in FIG. 8 is combined to the bottom chassis 300 of the LCD deviceby using the first securing member 910 according to an embodiment of thepresent invention.

Referring to FIGS. 10 and 11, the second locking hole 315 is formed onthe bottom chassis 300 and an area of the bottom chassis 300 adjacent tothe second locking hole 315 is projected at a predetermined height. But,the second locking hole 315 has a lower height than the highest part ofthe parts constructing the A/D board 400 and the inverter board 500 thatare combined to the back surface of the bottom chassis 300.

As shown in FIG. 11, the second power supply line 262 a is enclosed bymeans of a flexible securing band 912 in a bundle. The flexible securingband 912 enclosing the second power supply line 262 a has first andsecond thru-holes 913 a and 913 b at both ends thereof.

When enclosing the second power supply line 262 a, the flexible securingband 912 has an adjusted length so that the first and second thru-holes913 a and 913 b face to each other. After the first and secondthru-holes 913 a and 913 b are corresponding to the second locking hole315 of the bottom chassis 300, the flexible securing band 912 iscombined to the second locking hole 315 by using the first locking screw914.

As shown in FIG. 10, the first locking screw 914 extends through thefirst and second thru-holes 913 a and 913 b and through the secondlocking hole 315 in turn to be combined with the back surface of thebottom chassis 300. As described above, the area of the bottom chassis300 adjacent to the second locking hole 315 is projected at thepredetermined height from the back surface of the bottom chassis 300 toprovide a space in which the first locking screw 914 is combined to thesecond locking hole 315. The second power supply line 262 a is securedto the bottom chassis 300 by means of the flexible securing member 912within a range of the height of the second locking hole 315.

Meanwhile, FIGS. 12 and 13 show a construction in which the first andsecond power supply lines 261 a and 262 a are secured to the backsurface of the bottom chassis 300 by using a second securing member 920according to another embodiment of the present invention.

Referring to FIGS. 12 and 13, first and second securing elements 922 and924 are formed on the back surface of the bottom chassis 300. The firstand second securing elements 922 and 924 are formed by partially cuttingthe bottom surface portion of the bottom chassis 300 to provide a spacebetween the first and second securing elements 922 and 924 and thebottom chassis 300. Furthermore, the first and second securing elements922 and 924 are spaced at a predetermined distance apart from eachother. The second securing element 924 has a third thru-hole 924 aformed therein. The third thru-hole 924 a may be formed in the firstsecuring element 922 or in the respective first and second securingelements 922 and 924.

The second securing member 920 has a securing segment 926 for securingthe second power supply line 262 a received between the first and secondsecuring elements 922 and 924. The securing segment 926 has asemi-cylindrical body 926 a to provide a space in which the second powersupply line 262 a is received between the securing segment 926 and thebottom chassis 300. First and second wings 926 b and 926 c extendoutwardly at a predetermined length from both ends of the body 926 a.The second wing 926 c has a fourth thru-hole 924 b corresponding to thethird thru-hole 924 a formed in the second securing element 924.

As shown, the second power supply line 262 a is received in thesemi-cylindrical body 926 a. In this state, when the securing segment926 is pushed to a side of the first and second securing elements 922and 924, the first and second wings 926 b and 926 c are respectivelyinserted into the space between the first and second securing elements922 and 924 and the bottom chassis 300 below the first and secondsecuring elements 922 and 924.

At that time, the securing segment 926 is inserted into the first andsecond securing elements 922 and 924 so that the third thru-hole 924 aformed in the second securing elements 924 faces to the fourth thru-hole924 b formed in the second wing 926 c. Next, when the second lockingscrew 928 is locked to extend through the third and fourth thru-holes924 a and 924 b, the second power supply line 262 a is secured to theback surface of the bottom chassis 300 as shown in FIG. 12.

If the first and second power supply lines 261 a and 262 a are notsecured to the back surface of the bottom chassis 300 by using the firstor second securing member 910 and 920, the first and second power supplylines 261 a and 262 a extending to the inverter board 500 are separatedfrom the back surface of the bottom chassis 300. As a result, the firstand second power supply lines 261 a and 262 a repeatedly collide withother structures on the back surface of the bottom chassis 300, so thatthe coating of the first and second power supply lines 261 a and 262 acan become damaged.

Accordingly, an exposed electric wire of the first and second powersupply lines 261 a and 262 a can be caused to short with the otherconductive elements, for example circuit parts of the integrated PCB 276and the inverter board 500. If the first and second power supply lines261 a and 262 a are not secured to a certain position on the bottomchassis 300, furthermore, the first and second power supply line 261 aand 262 a interrupt the assembling of another structure at the nextassembly step, resulting in not performing the process of assembling theLCD device. Similarly, the first power supply line 261 a is also securedto the back surface of the bottom chassis 300 by means of the samesecuring member as is the first or second securing member 910 or 920 forsecuring the second power supply line 262 a to the bottom chassis 300.

As described above, after the A/D board 400 and the inverter board 500are combined to the back surface of the bottom chassis 300, and afterthe first and second power supply lines 261 a and 262 a are connected tothe inverter board 500, the shield case 700 is combined to the backsurface of the bottom chassis 300.

FIG. 14 is a plan view showing the construction of the shield case 700shown in FIG. 5, and FIG. 15 is a view of showing the LCD monitor ofwhich the shield case 700 shown in FIG. 10 is combined to the backsurface.

Referring to FIG. 14, the shield case 700 protects the A/D board 400 andthe inverter board 500 mounted on the bottom chassis 300 while isolatingthe electromagnetic waves from the A/D board 400 and the inverter board500.

Ninth, tenth, eleventh and twelfth locking holes 340 a, 342 a, 346 a and347 a are formed in a bottom surface of the shield case 700 to becorresponding to third, fourth, seventh and eighth locking holes 340,342, 346 and 347 formed in the bottom chassis 300.

On the other hand, first and second openings 710 and 712 are formed in aregion of the shield case 700 that covers the inverter board 500 tofacilitate a discharge of heat generated from the inverter board 500.Particularly, it is preferable that the first and second openings 710and 712 are formed in the shield case 700 at a position adjacent to anelement generating a large amount of heat, such as a transformer (notshown) of the circuit parts constructing the inverter board 500.

Furthermore, a part of the shield case 700 is cut to form first andsecond windows 722 and 724. The worker can identify through the firstand second windows 722 and 724 whether the line 263 for electricallyconnecting the inverter board 500 with the A/D board 400 is normallyconnected with the second and ninth connectors 412 and 516 (not shown inFIGS. 14-15).

If the first and second windows 722 and 724 are not formed in the shieldcase 700, the worker or a user must dismantle and combine the bottomchassis 300 from/with the shield case 700 every time in order toidentify whether the connectors connecting the integrated PCB 276 withthe A/D board 400, or the A/D board 400 with the inverter board 500, arenormally connected with each other.

Furthermore, the shield case 700 has first and second connectionsegments 730 and 740 formed by cutting a predetermined portion of asidewall of the shield case 700. After the shield case 700 is mounted onthe back surface of the bottom chassis 300, the worker can connect theline for supplying the outer electric power to the inverter board 500and the line for providing the outer data signals to the A/D board 400to the sixth connector 512 and the third connector 414 (not shown inFIGS. 14-15) through the first and second connection segments 730 and740, respectively.

However, the sidewall in which the first and second connection segments730 and 740 are formed is not completely opened. In other words, thefirst and second connection segments 730 and 740 are formed in anopening closed by the shield case 700. In the preferred embodiment ofthe present invention, the first and second connection segments 730 and740 are partially connected with each other at bottom portions thereofby means of first and second connecting parts 731 and 741. As the firstand second connection segments 730 and 740 are formed in a closed formas described above, the capability of the shield case 700 for insulatingthe electromagnetic wave can be improved.

Meanwhile, the shield case 700 has a relatively narrower width in a mostportion thereof except for the end which protects the integrated PCB276. This is because the A/D board 400 and the inverter board 500 arecovered with the shield case 700 to isolate the electromagnetic wavesand are concentrically mounted at the center portion of the bottomchassis 300.

Referring to FIGS. 8 and 15, particularly, even though the A/D board 400and the inverter 500 are combined to the back surface of the bottomchassis 300, most of the back surface of the bottom chassis 300 and themold frame 600 is exposed, except for a region, in which the integratedPCB 276, the A/D board 400 and the inverter board 500 are mounted. Inaddition, the shield case 700 is a member for isolating theelectromagnetic waves generated from the integrated PCB 276, the A/Dboard 400 and the inverter board 500. Even if the shield case 700 iscombined to the back surface of the bottom chassis 300, accordingly,most of the edge of the bottom chassis 300 and of the mold frame 600 isexposed as shown in FIG. 15.

When the front case 210 is faced and combined to the rear case 220 afterthe shield case 700 is mounted on the back surface of the bottom chassis300 as described above, the assembly of the LCD monitor is completed asshown in FIGS. 16 and 17.

FIGS. 16 and 17 are perspective views showing an exterior of the LCDmonitor device shown in FIG. 5.

Referring to FIGS. 16 and 17, the thickness t3 of the edge of the LCDdevice, to which the front and rear cases 210 and 220 are combined, issmaller than the thickness t4 of the center portion of the bottomchassis 300 on which the A/D board 400 and the inverter board 500 aremounted. As described already, this is because the shield case 700covers only the region in which the integrated PCB 276, the A/D board400 and the Inverter board 500 are mounted.

In order to use the LCD device, a support 800 for supporting the LCDdevice has to be connected to the rear case 220.

As shown in FIGS. 16 and 17, the support 800 includes a cover 810 havinga recess for receiving the projected center portion of the rear case 220and abutments 820 and 830, which are combined to the cover 810, forproviding a supporting force to the cover 810.

In FIGS. 16 and 17, in the state that the rear case 220 covers theshield case 700, the cover 810 of the support 800 receives the projectedcenter portion of the rear case 220. However, the rear case 220 may bepartially cut so that the shield case 700 is exposed outside. In otherwords, after a region of the rear case 220 corresponding to the shieldcase 700 is opened, the shield case 700 that is exposed out of the rearcase 220 is covered with the cover 810 of the support 800. In this case,the total thickness t5 of the LCD device, including the thickness of thecover 810 of the support 800, becomes thinner. As a result, the thin andlighter LCD monitor can be obtained.

According to the LCD device as described above, the inverter board 500for supplying the electric power to the lamp unit and the A/D board 400,for converting and providing the outer data signals to the integratedPCB are in direct and close contact to and combined with the backsurface of the bottom chassis 300.

Furthermore, the shield case for isolating the electromagnetic wavesgenerated from the A/D board 400 and the inverter board 500 covers theA/D board 400 and the inverter board 500 so that the edges of the bottomchassis 300 and the mold frame 600 are exposed.

Therefore, it is possible to manufacture the LCD device having an edgein which its thickness is the same as a total thickness of a LCD module.Accordingly, the total thickness of the LCD device is minimized, so thatthe thin and lighter LCD device can be obtained.

Although the preferred embodiments of the present invention have beendescribed, it is understood that the present invention should not belimited to these preferred embodiments but various changes andmodifications can be made by one skilled in the art within the spiritand scope of the present invention as hereinafter claimed.

1. A liquid crystal display device comprising: display unit to displayan image; receiving unit to receive the display unit; a printed circuitboard mounted on a back surface of the receiving unit, to control anoperation of the display unit; and shielding unit mounted on the backsurface of the receiving unit, to shield electromagnetic waves from theprinted circuit board, wherein the shielding unit is mounted on a centerportion of the back surface of the receiving unit while enclosing theprinted circuit board so that at least two opposite edges of thereceiving unit are exposed at a predetermined width.
 2. The liquidcrystal display device of claim 1, wherein the receiving unit includes abottom chassis to receive the display unit and a mold frame having abottom surface opened so that a back surface of the bottom chassis inwhich the printed circuit board is mounted is exposed, for receiving thebottom chassis.
 3. The liquid crystal display device of claim 2, whereinthe shielding unit has a smaller area than either of the bottom chassisand the mold frame.
 4. The liquid crystal display device of claim 1,wherein the printed circuit board includes at least one of a powersupply unit and a single converting unit mounted on the back surface ofthe receiving unit, the power supply unit supplies power to the displayunit and the signal converting unit converts signals supplied to thedisplay unit.
 5. The liquid crystal display device of claim 4, whereinthe display unit includes an integrated printed circuit boardelectrically connected to the signal converting unit with a flexibleprinted circuit board, for controlling the operation and an operatingtime of the display unit in response to the signals from the powersupply unit and the signal converting unit.
 6. The liquid crystaldisplay device of claim 5, wherein the integrated printed circuit boardincludes a data side printed circuit board and a gate side printedcircuit board, which is combined with only one side of the display unit.7. The liquid crystal display device of claim 4, further comprising: apower supply line for supplying the power from the power supply unit toa lamp of the display unit; and a fixing member for fixing the powersupply line to the back surface of the receiving unit.
 8. The liquidcrystal display device of claim 7, wherein the fixing member includes abelt type fixing band having a first through-hole and secondthrough-hole arranged at opposite ends of the belt type fixing band andthe belt type fixing band is bent so that the first through-hole and thesecond through-hole are adjacent to each other to receive the powersupply line and a first locking screw that extends through the firstthrough-hole and the second through-hole of the belt type fixing bandwhich is bent to receive the power supply line and fixed to the bottomchassis.
 9. A liquid crystal display device, comprising: a displayingdevice having a display unit to display an image, receiving unit toreceive the display unit, a printed circuit board mounted on a backsurface of the receiving unit to control an operation of the displayunit, and shielding unit mounted at a center portion of the back surfaceof the receiving unit such that the receiving unit has two exposedopposite edges, the shielding unit shields electromagnetic waves fromthe printed circuit board; a front case for receiving the displayingdevice in front of the displaying device; and a rear case combined withthe front case in back of the displaying device, wherein the rear casehas a region projecting at a predetermined height to receive theshielding unit.
 10. The liquid crystal display device of claim 9,further comprising an abutment combined with the projected region in aback surface of the rear case, to support the displaying unit.
 11. Aliquid crystal display device, comprising: displaying unit to display animage; receiving unit that includes a bottom chassis to receive thedisplaying unit; a printed circuit board mounted on a back surface ofthe receiving unit to control an operation of the displaying unit, theprinted circuit board including a power supply unit mounted on the backsurface of the receiving unit to supply power to the displaying unit; apower supply line to supply the power from the power supply unit to alamp of the displaying unit; a securing member including a belt typesecuring band that has a first through-hole and a second through-holearranged at each end of the securing band and bent so that the firstthrough-hole and the second through-hole are arranged adjacent to eachother in order to receive the power supply line, and a first lockingscrew that extends through the first through-hole and the secondthrough-hole of the securing band to secure the securing band to thebottom chassis, the securing member securing the power supply line tothe back surface of the receiving unit; and shielding unit mounted onthe back surface of the receiving unit to cover the printed circuitboard so as to shield electromagnetic waves from the printed circuitboard, wherein the shielding unit is mounted on a center portion of theback surface of the receiving unit while enclosing the printed circuitboard so that edges of the receiving unit are exposed at a predeterminedwidth.
 12. A liquid crystal display device, comprising: displaying unitto display an image; receiving unit to receive the displaying unit; aprinted circuit board mounted on a back surface of the receiving unit tocontrol an operation of the displaying unit; shielding unit mounted onthe back surface of the receiving unit covering the printed circuitboard and shielding electromagnetic waves from the printed circuitboard; a front case combined with the receiving unit in front of thereceiving unit; and a rear case combined with the front case in back ofthe shielding unit, wherein the front case and rear case have a firstthickness at a position corresponding to edges of the receiving unit andthe front case and the rear case have a second thickness, which isthinner than the first thickness, the second thickness at a positioncorresponding to the shielding unit.
 13. The liquid crystal displaydevice of claim 12, wherein the receiving unit includes a bottom chassisto receive the displaying unit and a mold frame, the mold frame has anopening in a bottom surface so that a back surface of the bottom chassisin which the printed circuit board is mounted is exposed.
 14. The liquidcrystal display device of claim 13, wherein the shielding unit has asmaller area than an area of the bottom chassis and the mold frame. 15.The liquid crystal display device of claim 13, wherein the printedcircuit board includes at least one of a power supply unit and a signalconverting unit mounted on the back surface of the receiving unit, andwherein the power supply unit supplies power to the displaying unit andthe converting unit converts signals supplied to the displaying unit.16. The liquid crystal display device of claim 15, wherein thedisplaying unit includes an integrated printed circuit boardelectrically connected to the signal converting unit via a flexibleprinted circuit board, to control the operation and an operating time ofthe displaying unit in response to signals from the power supply unitand from the signal converting unit.
 17. The liquid crystal displaydevice of claim 16, wherein the integrated printed circuit boardincludes a data side printed circuit board and a gate side printedcircuit board, which are combined with only one side of the displayingunit.
 18. The liquid crystal display device of claim 15, furthercomprising: a power supply line to supply the power from the powersupply unit to a lamp of the displaying unit; and a securing member tosecure the power supply line to the back surface of the receiving unit.19. The liquid crystal display device of claim 18, wherein the securingmember includes a belt type securing band that has first though-hole andsecond through-hole arranged at opposite ends of the belt type securingband, wherein the belt type securing band is bent so that the firstthrough-hole and second through-hole are adjacent to each other toreceive the power supply line, and wherein a first locking screw extendsthrough the first through-hole and second through-hole of the belt typesecuring band to secure the securing band to the bottom chassis.
 20. Aliquid crystal display device, comprising: a display device including adisplay unit to display an image, a receiving unit to receive thedisplay unit, a printed circuit board mounted on a back surface of thereceiving unit to control an operation of the display unit, andshielding unit mounted at a center portion of the back surface of thereceiving unit to shield electromagnetic waves from the printed circuitboard; a front case combined with the display device in front of thedisplay device; and a rear case combined with the front case in back ofthe shielding unit, the rear case includes a projecting region thatextends to a predetermined height to receive the shielding unit, whereina portion of the front case and rear case have a first thickness at aposition corresponding to edges of the receiving unit and a secondthickness, which is thinner than the first thickness, at a positioncorresponding to the shielding unit.
 21. The liquid crystal displaydevice of claim 20, further comprising an abutment combined with theprojecting region in a back surface of the rear case, to support thedisplay device.